BEIJING – American and Chinese companies signed more than a dozen deals worth $9 billion as President Trump arrived in China on Wednesday for a visit likely to be dominated by tough trade talks and tensions over North Korea's nuclear program.

No details of the 19 agreements signed at a ceremony in Beijing attended by U.S. Commerce Secretary Wilbur Ross and China's vice-premier Wang Yang were immediately released, but such business contracts are a common fixture of visits by foreign leaders to China.

Before arriving in Beijing, Trump used a speech to South Korea’s National Assembly to call on China to stop supporting North Korea, China’s largest trading partner. He said "all responsible nations" needed to isolate Pyongyang.

In a direct threat to the North's leader Kim Jong Un, Trump said that "your weapons are not making you safer ... Do not underestimate us. Do not try us."

More: Trump warns North Korea not to 'try us' with nuclear weapons

The president arrived in Beijing to a lavish reception and had tea with President Xi Jinping and his wife, Madame Peng Liyuan, followed by a tour of the Forbidden City, a 15th-century compound that housed China's imperial palace for several dynasties.

Trump is expected to air grievances about Chinese trade practices and urge China to buy more American products. Last week he said that the U.S. trade deficit with China — $347 billion last year — is "so bad that it’s embarrassing."

"I don’t want to embarrass anybody four days before I land in China, but it’s horrible," said Trump.

Most of those discussions are nevertheless being saved for Thursday. Wednesday was for ceremony.

The president and first lady Melania Trump were greeted at the airport by dozens of children who waved U.S. and Chinese flags and jumped up and down.

After touring Beijing’s ancient imperial palace, including a performance by young opera students before a formal dinner, Trump said he was "having a great time" in China.

Trump is on a five-country, 12-day trip through Asia traveling to Japan, South Korea, China, Vietnam and the Philippines.